scholarly journals Determining the Radiation Enhancement Effects of Gold Nanoparticles in Cells in a Combined Treatment with Cisplatin and Radiation at Therapeutic Megavoltage Energies

2021 ◽  
Author(s):  
Celina Yang ◽  
Kyle Bromma ◽  
Wonmo Sung ◽  
Jan Schuemann ◽  
Devika B. Chithrani

Combined use of chemotherapy and radiation therapy is commonly used in cancer treatment, but the toxic effects on normal tissue are a major limitation. This study assesses the potential to improve radiation therapy when combining gold nanoparticle (GNP) mediated radiation sensitization with chemoradiation compared to chemoradiation alone. Incorporation of GNPs with 2 Gy, 6 MV (megavoltage) radiation resulted in a 19 ± 6% decrease in survival of MDA-MB-231 cells. Monte-Carlo simulations were performed to assess dosimetric differences in the presence of GNPs in radiation. The results show that physics dosimetry represents a small fraction of the observed effect. The survival fraction of the cells exposed to GNPs, cisplatin, and radiation was 0.16 ± 0.007, while cells treated with cisplatin and radiation only was 0.23 ± 0.011. The presence of GNPs resulted in a 30 ± 6% decrease in the survival, having an additive effect. The concentration of the GNPs and free drug used for this study was 0.3 and 435 nM, respectively. These concentrations are relatively lower and achievable in an in vivo setting. Hence, the results of our study would accelerate the incorporation of GNP-mediated chemoradiation into current cancer therapeutic protocols in the near future

2021 ◽  
Author(s):  
Celina Yang ◽  
Kyle Bromma ◽  
Wonmo Sung ◽  
Jan Schuemann ◽  
Devika B. Chithrani

Combined use of chemotherapy and radiation therapy is commonly used in cancer treatment, but the toxic effects on normal tissue are a major limitation. This study assesses the potential to improve radiation therapy when combining gold nanoparticle (GNP) mediated radiation sensitization with chemoradiation compared to chemoradiation alone. Incorporation of GNPs with 2 Gy, 6 MV (megavoltage) radiation resulted in a 19 ± 6% decrease in survival of MDA-MB-231 cells. Monte-Carlo simulations were performed to assess dosimetric differences in the presence of GNPs in radiation. The results show that physics dosimetry represents a small fraction of the observed effect. The survival fraction of the cells exposed to GNPs, cisplatin, and radiation was 0.16 ± 0.007, while cells treated with cisplatin and radiation only was 0.23 ± 0.011. The presence of GNPs resulted in a 30 ± 6% decrease in the survival, having an additive effect. The concentration of the GNPs and free drug used for this study was 0.3 and 435 nM, respectively. These concentrations are relatively lower and achievable in an in vivo setting. Hence, the results of our study would accelerate the incorporation of GNP-mediated chemoradiation into current cancer therapeutic protocols in the near future


2017 ◽  
Vol 19 (suppl_6) ◽  
pp. vi79-vi79 ◽  
Author(s):  
Brandon Nicolay ◽  
Rohini Narayanaswamy ◽  
Michael D Amatangelo ◽  
Elia Aguado ◽  
Raj Nagaraja ◽  
...  

2018 ◽  
Vol 28 (6) ◽  
pp. 642-646 ◽  
Author(s):  
Shoko Merrit Yamada ◽  
Yusuke Tomita ◽  
Soichiro Shibui ◽  
Mikiko Takahashi ◽  
Masashi Kawamoto ◽  
...  

Astroblastoma is a rare tumor that is thought to occur exclusively in the cerebrum. To the authors’ knowledge, no cases of spinal cord astroblastoma have been reported. A 20-year-old woman presented with numbness in her legs. MRI demonstrated a 2-cm intramedullary enhancing lesion in the spinal cord at the T-1 level. The patient declined to undergo resection of the tumor because she was able to walk unassisted; however, she returned for surgery 1 month later because she had developed paraplegia with bladder and rectal dysfunction, and MRI showed enlargement of the tumor. Intraoperatively, the border between the tumor and normal tissue was poorly defined. Biopsy samples were obtained for histopathological examinations, and a diagnosis of astroblastoma with a Ki-67 index of 5% was made. Considering the rapid tumor growth on MRI and remarkable deterioration in her symptoms, the patient was treated with a combination of radiation therapy, temozolomide (TMZ), and bevacizumab. After completion of the combined treatment, she was able to move her toes, and oral TMZ and bevacizumab injections were continued. Six months later, definite tumor shrinkage was identified on MRI, and the patient was able to stand up from a wheelchair without assistance and walk by herself. No therapeutic regimens for residual astroblastoma are established; however, in this case the authors’ therapeutic strategy was successful in treating the spinal cord astroblastoma.


2011 ◽  
Vol 55 (6) ◽  
pp. 2655-2661 ◽  
Author(s):  
Gilles Brackman ◽  
Paul Cos ◽  
Louis Maes ◽  
Hans J. Nelis ◽  
Tom Coenye

ABSTRACTAlthough the exact role of quorum sensing (QS) in various stages of biofilm formation, maturation, and dispersal and in biofilm resistance is not entirely clear, the use of QS inhibitors (QSI) has been proposed as a potential antibiofilm strategy. We have investigated whether QSI enhance the susceptibility of bacterial biofilms to treatment with conventional antimicrobial agents. The QSI used in our study target the acyl-homoserine lactone-based QS system present inPseudomonas aeruginosaandBurkholderia cepaciacomplex organisms (baicalin hydrate, cinnamaldehyde) or the peptide-based system present inStaphylococcus aureus(hamamelitannin). The effect of tobramycin (P. aeruginosa,B. cepaciacomplex) and clindamycin or vancomycin (S. aureus), alone or in combination with QSI, was evaluated in variousin vitroandin vivobiofilm model systems, including two invertebrate models and one mouse pulmonary infection model.In vitrothe combined use of an antibiotic and a QSI generally resulted in increased killing compared to killing by an antibiotic alone, although reductions were strain and model dependent. A significantly higher fraction of infectedGalleria mellonellalarvae andCaenorhabditis eleganssurvived infection following combined treatment, compared to treatment with an antibiotic alone. Finally, the combined use of tobramycin and baicalin hydrate reduced the microbial load in the lungs of BALB/c mice infected withBurkholderia cenocepaciamore than tobramycin treatment alone. Our data suggest that QSI may increase the success of antibiotic treatment by increasing the susceptibility of bacterial biofilms and/or by increasing host survival following infection.


Author(s):  
V. Mohan ◽  
N. M. Bruin ◽  
J. B. van de Kamer ◽  
J.-J. Sonke ◽  
Wouter V. Vogel

AbstractRadiation therapy is an effective treatment modality for a variety of cancers. Despite several advances in delivery techniques, its main drawback remains the deposition of dose in normal tissues which can result in toxicity. Common practices of evaluating toxicity, using questionnaires and grading systems, provide little underlying information beyond subjective scores, and this can limit further optimization of treatment strategies. Nuclear medicine imaging techniques can be utilised to directly measure regional baseline function and function loss from internal/external radiation therapy within normal tissues in an in vivo setting with high spatial resolution. This can be correlated with dose delivered by radiotherapy techniques to establish objective dose-effect relationships, and can also be used in the treatment planning step to spare normal tissues more efficiently. Toxicity in radionuclide therapy typically occurs due to undesired off-target uptake in normal tissues. Molecular imaging using diagnostic analogues of therapeutic radionuclides can be used to test various interventional protective strategies that can potentially reduce this normal tissue uptake without compromising tumour uptake. We provide an overview of the existing literature on these applications of nuclear medicine imaging in diverse normal tissue types utilising various tracers, and discuss its future potential.


Author(s):  
M. G. Markova ◽  
E. N. Somova

Work on going through the adaptation stage of rooted micro-stalks comes down to searching for new growth regulators and studying the influence of external conditions, which include, among other things, light effects. The data of 2018-2019 on the effect of growth regulators Siliplant, EcoFus and experimental LED phytoradiators on the adaptation of rooted micro-stalks of garden strawberries (Fragaria x ananassa duch) in vivo are presented. The object of research is rooted micro-stalks of garden strawberries of the Korona variety. It was revealed that, at the adaptation stage of rooted micro-stalks of strawberries, the most effective was the treatment of plants by spraying with Siliplant at a concentration of 1.0 ml/l and the combined treatment with Siliplant and EcoFus at concentrations of 0.5 ml/l: regardless of lighting, the survival rate averaged 99.4 - 99.7%, the leaf surface area increased significantly from 291.85 mm2 to 334.4 mm2. The number of normally developed leaves of strawberry microplants increased significantly after treatment with all preparations from 3.5 to 6.0, 5.8 and 6.5 pcs/plant, and a significant increase in the height of strawberry rosettes was facilitated by treatment with Siliplant and Siliplant together with EcoFus. Regardless of growth regulators, the most effective was the experimental LED phyto-irradiator with a changing spectrum, which contributed to an increase in leaf surface area, height of rosettes and the number of normally developed leaves in strawberry microplants. When illuminated with a flashing phytoradiator, these indicators are lower than in the control version, but not significantly. By the end of the rooting stage, all microplants of garden strawberries corresponded to GOST R 54051-2010.


10.37206/88 ◽  
2005 ◽  
Author(s):  
Ellen Yorke ◽  
Rodica Alecu ◽  
Li Ding ◽  
Doracy Fontenla ◽  
Andre Kalend ◽  
...  

2018 ◽  
Vol 64 (1) ◽  
pp. 54-61
Author(s):  
A. Ryabova ◽  
O. Gribova ◽  
V. Novikov ◽  
E. Choinzonov ◽  
Zh. Starceva ◽  
...  

Unsatisfactory results of complex treatment for malignant brain tumors stimulate search of new effective methods of treatment. Radiation therapy is an integral part of the combined treatment but often does not influence lethally on resistant tumor cells. Thereby in recent decades there has been an active search for different modifiers, which can increase the sensitivity of tumors to chemotherapy and radiotherapy. One of the universal sensitizers is the local hyperthermia. Experimental data showed that the effect of high temperatures had both a direct damaging effect on tumor cells and a sensitizing effect. The literature review given in the article provides an overview of the existing methods of the local hyperthermia for brain tumors treatment.


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